and today, president obama traveled to minneapolis to raise pressure for gun legislation. here's abc's chief white house correspondent jonathan karl. >> reporter: faced with an uphill battle in congress, the president took his campaign for new gun control measures on the road today. >> we're not going to wait until the next newtown. >> reporter: a essential cal component of the president's plan is requiring virtually anybody buying a gun to get a background check. but the audience in minneapolis has seen first-hand that that's not enough. last september, just a few miles from where the president spoke, minnesota suffered its worst ever mass shooting. 36-year-old andrew engeldinger went on a rampage at this sign store after he was fired. shooting and killing six employees before turning the gun on himself. according to engeldinger's parents, he was mentally ill and had refused treatment. but here's the thing -- he legally bought his gun here after passing a background check. >> our son struggled for years with mental illness. in the last few years, we have no longer had con